I would suggest about 1600 also. There is no magic number, it's basically trial and error. Try it out for a few weeks, see how it goes, and tweak it from there. Don't feel bad about a 1680 day. It takes 3500 calories more/less than you need to gain/lose a pound. You didn't do any damage

UWPiPhiAngel-
use the custom foods option. Alot of the foods I eat aren't on there, either. You can enter them in once by using the nutrition facts label to get calories/fat/carbs, etc on whatever you're eating, and fitday will save it to your list. Restaurant/takeout food is the only place we are truly screwed, lol. You just have to guess.